why does the Earth move? – Ecosystems Zone

Question: why does the Earth move?
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  Earth
Asked by Jade and Freya RULE ! to Hannah, Joanna, Joe, Luis, Vincent on 16 Jun 2016.
- Hannah Grist answered on 16 Jun 2016:
  
  That’s a cool question :-). I’m not a physicist, but I’ll try and answer!
  
  I assume you mean why does the earth turn, rather than why does it go round the sun. The earth spins completely round every 24 (ish) hours, which is why it looks like the sun rises and sets. The reason is spins is because it started spinning when it was formed, billions of years ago. The earth was made by lots of dust and energy coming together to form a lump, that started spinning. Because there is nothing in space to stop it spinning (the way air stops things spinning eventually on earth), it has just never stopped!
- Joanna Bagniewska answered on 17 Jun 2016:
  
  In that case I will try answer the other side of the question – why does the Earth move around the Sun.
  
  There is a force that attracts the Earth to the Sun (basically because big things like that attract each other). That force means that the Earth has to go around the Sun – otherwise it would fly in a straight line, past the Sun. It’s like a tennis ball that you throw in the air – if you throw it straight, it will go in one line. But if you attach a string to it, and try to throw it while the other end is tied to a pole, the ball will have to start curving its path, and going around in a circle, with the pole in the middle. In space, the Earth is like the ball, the Sun is like the pole, and the string is the force between them.
  
  I asked my husband, who is a physicist, why the Earth is moving in the first place. Apparently it is because at some point it started to move, and, because there is no friction in space to stop it, it will continue to move. Unfortunately we don’t yet know why it started moving in the first place.
- Vincent Keenan answered on 20 Jun 2016:
  
  The earth is currently trapped in the Sun’s orbit and that is due to gravity – a rather mysterious force that no one can fully explain. The earth rotates due to something called “conservation of angular momentum”, which starts with the formation of the sun (from gravity) and whatever is left over (something called an accretion disk, or protoplanetary disk) is what the remaining planets are made from. But because they are turning and falling through space, they also come together under gravity. All of that spinning motion is conserved, and is expressed in a rotation. Well that is one theory…
- Joe Nunez-Mino answered on 22 Jun 2016:
  
  This is a huge question and one that has already been answered very well. I’m glad the earth does move otherwise some places on earth would be permanently cold and dark!

Question: why does the Earth move?

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